title: Production and characterization of alkaline protease from hemoglobin-degrading Bacillus pumilus NJM4 to produce fermented blood meal.
abstract: The aim of the research was to isolate the hemoglobin-degrading bacterial strain to produce fermented blood meal and to characterize the protease produced by this strain. The strain NJM4, a kind of hemoglobin-degrading bacterial strain, was isolated by blood agar plates from slaughterhouse and identified as a Bacillus pumilus by physiological, biochemical, and morphological characteristics and by 16S rRNA gene sequencing. Bacillus pumilus NJM4 could degrade hemoglobin up to 85% in 36 h under the laboratory conditions. The optimal conditions for protease production was achieved at an initial pH level of 8.67, inoculum size of 4%, incubation temperature of 37 °C, and agitation rate 200 rpm. The optimum pH and temperature of hemoglobin-degrading proteases were at 9.0 and 50 °C, respectively. The protease activity was slightly decreased in presence of Ca(2+) and DTT. It was significantly inhibited in the presence of PMSF and EDTA identifying it as alkaline serine-metalloproteinase. Bacillus pumilus NJM4 and hemoglobin-degrading proteases provide potential use for biotechnological process of fermentation and enzymolysis blood meal as animal feed supplement.
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu 210095 China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Yao
authors.forename: Jiao
authors.initials: J
authors.lastname: Qu
authors.forename: Peiwei
authors.initials: P
authors.lastname: Chang
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Tao
authors.forename: Deji
authors.initials: D
authors.lastname: Yang
keywords: Bacillus pumilus; Degradation; Hemoglobin; Protease